Unless it's sitting on top of a delicious cup of caffeinated person fuel, 'foam' isn't very interesting. But then composite metal foam isn't your average layer of bubbles.
Composite metal foam is the 'Superman' of foam - capable of stopping a speeding bullet dead in its tracks. Like this.
This incredible material is the work of a group of engineers at North Carolina State University, who've been experimenting with this unusual substance in quest to see just how useful it could be to the wider world.
Professor Afsaneh Rabiei has used this air-packed metal to create shields capable of blocking X-rays, gamma rays and neutron radiation - while this latest experiment shown above sees an inch of composite metal foam disintegrate a 7.62 x 63 mm M2 armour-piercing bullet.
"We could stop the bullet at a total thickness of less than an inch, while the indentation on the back was less than 8 mm," said Rabiei. "To put that in context, the US National Institute of Justice standard [for ballistic tests] allows up to 44 mm (1.73 in) indentation in the back of an armour."
Incredible - and a lot cooler than anything a barista can cook up with hot milk.